November a strong contrast to October's unusual warmth

November in Berks County has gone in the opposite direction of October in terms of temperature.

At the halfway point, the month has turned cold, unlike the warm October. But like October, rainfall has been sparse.

The first freezing temperature was a bit late in arriving, coming on Nov. 9. The first for a 32 is typically in the final days of October.

But since Nov. 9, freezing or lower has been recorded on six days, including Wednesday, fueling a month that is about 3 degrees below normal. October was more than 6 degrees above normal.

The arctic incursion of Friday and Saturday set records.

The low temperature of 20 on Friday was a record, bettering a 21 from 2003; the 18 on Saturday tied a mark from 1973.

Both were among the coldest readings in the first half of November in the nearly 12-decade temperature database.

Lower-lying areas were even colder. In Gibraltar, 11 degrees was recorded Saturday.

Record low minimum temperatures have been rare this decade. More high temperature records have been set.

A La Nina has formed in the eastern equatorial Pacific Ocean. It is a cooling of the waters there. The National Weather Service expects it to run through the winter but be relatively weak.

La Ninas are often associated with frigid but not necessarily snowy winters in the mid-Atlantic. Part of it includes a blocking high pressure system over Greenland that can funnel bitter air into the eastern United States.

Jeffrey R. Stoudt, Berks weather historian and organizer of the Berks Area Rainfall Network, was impressed with the cold last weekend.

"I do not recall such magnitude of arctic air for this early in the Northern Hemisphere, save perhaps 1976," he said. "Except for 1976, nearly all the years which record lows occurred in early November had mild Decembers and winters with less harshness than usual."

November 1976 is the record holder for cold, a harsh month that set the stage for a harsher winter, including the coldest month in the record period: January 1977.

Stoudt had been seeing the pattern running in 2017 as similar to 1960, which culminated in a bitter winter in 1960-61. He says that analogy appears in doubt because of the historical precedence of the cold start to November.

On the other hand, with the La Nina and the blocking high, it might stay harsh.